Editing Kin selection (section)

=== Mechanisms in plants ===

The ability to differentiate between kin and non-kin is not necessary for kin selection in many animals.<ref name="File Murphy Dudley 2011">{{Cite journal |last1=File |first1=Amanda L. |last2=Murphy |first2=Guillermo P. |last3=Dudley |first3=Susan A. |date=9 November 2011 |title=Fitness consequences of plants growing with siblings: reconciling kin selection, niche partitioning and competitive ability |journal=Proceedings of the Royal Society B: Biological Sciences |volume=279 |issue=1727 |pages=209–218 |doi=10.1098/rspb.2011.1995 |issn=0962-8452 |pmc=3223689 |pmid=22072602}}</ref> However, because plants do not reliably germinate in close proximity to kin, it is thought that, within the plant kingdom, kin recognition is especially important for kin selection there, but the mechanism remains unknown.<ref name="File Murphy Dudley 2011"/><ref>{{Cite journal |last1=Dam |first1=Nicole M. van |last2=Bouwmeester |first2=Harro J. |date=March 2016 |title=Metabolomics in the Rhizosphere: Tapping into Belowground Chemical Communication |url=https://www.cell.com/trends/plant-science/abstract/S1360-1385(16)00009-1 |journal=Trends in Plant Science |volume=21 |issue=3 |pages=256–265 |doi=10.1016/j.tplants.2016.01.008 |issn=1360-1385 |pmid=26832948|bibcode=2016TPS....21..256V }}</ref>

One proposed mechanism for kin recognition involves communication through roots, with secretion and reception of [[Plant root exudates|root exudates]].<ref name="File Murphy Dudley 2011"/><ref name="Rahman Zhou Wu 2019">{{Cite journal |last1=Rahman |first1=Muhammad Khashi u |last2=Zhou |first2=Xingang |last3=Wu |first3=Fengzhi |date=5 Aug 2019 |title=The role of root exudates, CMNs, and VOCs in plant–plant interaction |journal=Journal of Plant Interactions |volume=14 |issue=1 |pages=630–636 |doi=10.1080/17429145.2019.1689581 |issn=1742-9145 |doi-access=free|bibcode=2019JPlaI..14..630K }}</ref><ref name="Biedrzycki Julany Dudley 2010">{{Cite journal |last1=Biedrzycki |first1=Meredith L. |last2=Jilany |first2=Tafari A. |last3=Dudley |first3=Susan A. |last4=Bais |first4=Harsh P. |date=Jan–Feb 2010 |title=Root exudates mediate kin recognition in plants |journal=Communicative & Integrative Biology |volume=3 |issue=1 |pages=28–35 |doi=10.4161/cib.3.1.10118 |issn=1942-0889 |pmc=2881236 |pmid=20539778}}</ref><ref name="Yang Li Xu 2018">{{Cite journal |last1=Yang |first1=Xue-Fang |last2=Li |first2=Lei-Lei |last3=Xu |first3=You |last4=Kong |first4=Chui-Hua |date=October 2018 |title=Kin recognition in rice ( Oryza sativa) lines |journal=New Phytologist  |volume=220 |issue=2 |pages=567–578 |doi=10.1111/nph.15296 |pmid=29956839 |s2cid=49590796 |doi-access=free |bibcode=2018NewPh.220..567Y }}</ref> This would require exudates to be actively secreted by roots of one plant, and detected by roots of neighboring plants.<ref name="Rahman Zhou Wu 2019"/><ref name="Biedrzycki Julany Dudley 2010"/> The root exudate allantoin produced by rice plants, ''[[Oryza sativa]]'', has been documented to be in greater production when growing next to cultivars that are largely unrelated.<ref name="Yang Li Xu 2018" /><ref name="Anten Chen 2021">{{Cite journal |last1=Anten |first1=Niels P. R. |last2=Chen |first2=Bin J. W. |date=April 2021 |title=Detect thy family: Mechanisms, ecology and agricultural aspects of kin recognition in plants |journal=Plant, Cell & Environment|volume=44 |issue=4 |pages=1059–1071 |doi=10.1111/pce.14011 |pmc=8048686 |pmid=33522615|bibcode=2021PCEnv..44.1059A }}</ref> High production levels of Allantoin correlated to up regulation of auxin and auxin transporters, resulting in increased lateral root development and directional growth of their roots towards non kin, maximizing competition.<ref name="Yang Li Xu 2018" /><ref name="Anten Chen 2021" /> This is mainly not observed in ''Oryza Sativa'' when surrounded by kin, invoking altruistic behaviors to promote inclusive fitness.<ref name="Yang Li Xu 2018" /> However the root [[Receptor (biochemistry)|receptors]] responsible for recognition of kin exudates, and the pathway induced by receptor activation, remain unknown.<ref name="Biedrzycki Julany Dudley 2010"/> The [[mycorrhiza]] associated with roots might facilitate reception of exudates, but again the mechanism is unknown.<ref>{{Cite journal |last1=Johnson |first1=David |last2=Gilbert |first2=Lucy |date=12 September 2014 |title=Interplant signalling through hyphal networks |journal=New Phytologist |language=en |volume=205 |issue=4 |pages=1448–1453 |doi=10.1111/nph.13115 |pmid=25421970 |doi-access=free}}</ref>

Another possibility is communication through [[green leaf volatiles]]. Karban et al. studied kin recognition in sagebrushes, ''[[Artemisia tridentata]]''. The volatile-donating sagebrushes were kept in individual pots, separate from the plants that received the volatiles, finding that plants responded to [[herbivore]] damage to a neighbour's leaves. This suggests that root signalling is not necessary to induce a [[Plant defense against herbivory|protective response against herbivory]] in neighbouring kin plants. Karban et al. suggest that plants may be able to differentiate between kin and non-kin based on the composition of volatiles. Because only the recipient sagebrush's leaves were exposed<ref name="Karban et al 2013"/> the volatiles presumably activated a [[Receptor (biochemistry)|receptor protein]] in the plant's leaves. The identity of this receptor, and the signalling pathway triggered by its activation, both remain to be discovered.<ref>{{Cite journal |last1=Bouwmeester |first1=Harro |last2=Schuurink |first2=Robert C. |last3=Bleeker |first3=Petra M. |last4=Schiestl |first4=Florian |date=Dec 2019 |title=The role of volatiles in plant communication |journal=The Plant Journal |volume=100 |issue=5 |pages=892–907 |doi=10.1111/tpj.14496 |issn=0960-7412 |pmc=6899487 |pmid=31410886}}</ref>